Cleanup histogram classes mixing SetFlags into FactoryGet arguments

Generic cleanup of histogram class, renaming *FactoryGet to FactoryGet,
along with reformatting.

The macros were cleaned up to use common sub-macros rather than
repeating code as much.

Removed ThreadSafeHistogram (and associated ASSET_HISTOGRAM macros)
since this class was not getting used.

I introduced UMA_HISTOGRAM_ENUMERATION to support the common use
of LinearHistograms to count various enumerated values.

I added a Flags argument to all the FactoryGet routines to help avoid 
needing to call SetFlags each time a new sample is Add()ed.  This also
simplifies the code.

This will all help prepare for a "don't histogram at all" macro setting
so that I can test the impact of the histogram macro calls on
performance (since there are now so many active histograms).

BUG=31206
r=raman.tenneti
Review URL: http://codereview.chromium.org/515033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35295 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 5 deletions

diff --git a/chrome/renderer/render_thread.cc b/chrome/renderer/render_thread.cc
index d1ce79d..632adab 100644
--- a/chrome/renderer/render_thread.cc
+++ b/chrome/renderer/render_thread.cc
@@ -505,13 +505,11 @@ static void* CreateHistogram(
     const char *name, int min, int max, size_t buckets) {
   if (min <= 0)
     min = 1;
-  scoped_refptr<Histogram> histogram =
-      Histogram::HistogramFactoryGet(name, min, max, buckets);
-  // We verify this was not being destructed by setting a novel "PlannedLeak"
-  // flag and watching out for the flag in the destructor.
-  histogram->SetFlags(kUmaTargetedHistogramFlag | kPlannedLeakFlag);
+  scoped_refptr<Histogram> histogram = Histogram::FactoryGet(
+      name, min, max, buckets, Histogram::kUmaTargetedHistogramFlag);
   // We'll end up leaking these histograms, unless there is some code hiding in
   // there to do the dec-ref.
+  // TODO(jar): Handle reference counting in webkit glue.
   histogram->AddRef();
   return histogram.get();
 }